Arsenal's Gabriel Martinelli celebrates scoring their first goal during the match Premier League between West Ham United vs Arsenal at London Stadium, London, December 9, 2019. Arsenal scored three quickfire second-half goals through Gabriel Martinelli, Nicolas Pepe and Pierre-Emerick Aubameyang to beat West Ham United 3-1. REUTERS/David Klein

Arsenal's Gabriel Martinelli scores their first goal during the match Premier League between West Ham United vs Arsenal at London Stadium, London, December 9, 2019. REUTERS/David Klein

Arsenal's Nicolas Pepe scores their second goal during the match Premier League between West Ham United vs Arsenal at London Stadium, London, December 9, 2019. REUTERS/David Klein

Arsenal's Nicolas Pepe celebrates scoring their second goal with teammate Pierre-Emerick Aubameyang during the match Premier League between West Ham United vs Arsenal at London Stadium, London, December 9, 2019. REUTERS/David Klein

Arsenal's Pierre-Emerick Aubameyang scores their third goal during the match Premier League between West Ham United vs Arsenal at London Stadium, London, December 9, 2019. REUTERS/David Klein

Arsenal's Pierre-Emerick Aubameyang celebrates scoring their third goal during the match Premier League between West Ham United vs Arsenal at London Stadium, London, December 9, 2019. REUTERS/David Klein